Re: [Matplotlib-users] General questions about Basemap

[Jeff W. <js...@fa...>]

Mauro Cavalcanti wrote:
> Dear ALL,
>
> I am using Basemap version 0.90 with MPL version 0.98.3 under Linux
> Ubuntu, both installed from Andrew Straw repository (I just prefer to
> install from repositories via apt than directly from the sources,
> although in this case I do not have always the latest versions).
>
> I stumbled upon a few issues that I could not solve by looking at the
> available documentation. They are not really critical for me, but I
> would be interested in finding some more about them anyway.
>
> Here they are:
>
> i) When trying some of the projections listed in the Basemap
> documentation, I got a message saying that this or that projection is
> not available, what leads me to think that these projections have only
> been included in later versions of Basemap. However, I could not find
> this in the documentation. This is not critical for my current
> project, as I have no need to offer so many projections, but I would
> like to know.
>   

Mauro:  Yes, the documentation applies to the current SVN version.  
Version 0.90 is rather old now.

> ii) The plotting of rivers using the drawrivers() method is painfully
> slow, even with resolution set to "crude". The FAQ provided with the
> Basemap source package offers an interesting suggestion for
> potentially solving this, but an exemple would be in order (the FAQ
> mentions an "ireland.py" example which I have however not found in the
> examples directory).
>   
I haven't noticed the rivers being slow, but I'll look into it.
> iii) In the same context as the above, I would be interested in
> knowing if there is some way to speed up the plotting of a map with
> the Blue Marble image superimposed on it.
>   
Plotting the blue marble image involves interpolating a very large array 
from lat/lon coordinates to projection coordinates.  So, no - there is 
no easy way to speed it up.  If you're only using a few different map 
projections and regions, you could pickle those basemap instances and 
re-use them, thereby saving the interpolation cost.  Using the "cyl" 
projection is reasonably fast, since there is no interpolation.
> In general, I would like to suggest that the Basemap FAQ could be
> expanded and made available in the website, along with, perhaps, some
> the examples provided in the Basemap distribution package (in the same
> way the examples are provided in the MPL page).
>   

I try to expand the docs in my spare time,  which I haven't had much of 
lately.  Volunteers are welcome!

-Jeff
> Well, hope this helps!
>
> Have a nice weekend.
>
> With best regards,
>
>   


-- 
Jeffrey S. Whitaker         Phone : (303)497-6313
NOAA/OAR/CDC  R/PSD1        FAX   : (303)497-6449
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